Apparatus for telephone-lines.



UNITED STATES I PATENT OFFICE.

' ALBERT M. BULLARD, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE WESTERN ELECTRIC COMPANY, OF SAME PLACE.

APPARATUS FOR TELEPHONE-LINES.

SPECIFICATION forming part of Letters Patent N 0; 679,068, dated July 23, 1901.

Application filed June 7,1899. Serial No. 719,642. (No model.)

To all whom, it may concern.-

Be it known that I, ALBERT M. BULLARD, a citizen of the United States, residing at Chicage, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Apparatus for Telephone- Lines, (Case No. 2,) of which the following is a full, clear, concise, and exact description.

My invention relates to telephone toll-line apparatus and circuits, and has for its object to provide improved means whereby a telephone-line extendingfrom a subscribers station to a central office may be controlled either at the subscribers station by the deposit of a coin or at the central office by the manipulation of certain mechanism there located independent of the coin-receiving ap paratus at the subscribers station-that is to say, it is the purpose of.my invention to provide a telephone toll-line apparatus and circuits whereby the deposit of a coin by the subscriber is necessary in order to transmit a signal to the central station in initiating a call, but whereby the operator at the central oflice may signal the subscribers station and may permit conversation to be had over the line without requiring the deposit of a coin.

In accordance with my invention the circuit of the telephone-line, while normally closed at'the central office through a line-indicator, is normally open at the subscribers station, two terminals being there provided for controlling the continuity of the talking and signaling circuit, between which terminals circuit may be completed in either of two waysfirst, by the deposit of a coin in the coin-receiving toll-box, or, second, by means of a relay through which current may be directed from the central office. In the circuit with the relay I preferably include a coindistributing electromagnet which may be operated from the central office to control the disposition of a coin which has been deposit: ed by the subscriber-that is to say, if the connection desired by the subscriber can be obtained the coin, which he has previously deposited in order to complete the signalingcircuit through his line-indicator, is directed into the cash-box. Otherwise the coin .may be directed into a return-chute leading to the outside of the box.

My invention will be more particularly described by reference to the accompanying drawing, which is a diagram illustrating by means of conventional symbols the several parts and circuit connections of the tele phone toll-line and central-office apparatus of myinvention. The subscribers station A is connected with the central office by means of the telephone-line a, having two branches a a which terminate in the line-springs b 6 respectively, of spring-jack b. The branch at of the telephone-line is normally connected through a line-indicator c to ground by way of the back contact d of the cut-off relay (1. The branch a of the telephone-line is likewise connected to ground through a battery or source of current e by Way of the back contact d of the cut-off relay.

At the subscribers station the usual telephone apparatus for talking is located, the talking-circuit being controlled in part by the switch-hook fin the usual manner. A highresistance polarized signal-bell g is permanently bridged across the telephone-line from a condenser g. The telephone system illustrated is that known as the common battery systemthat is, a system wherein the subscribers transmitter is supplied with current from a centralized battery at the ex- This is Well known and needs no further description.

There is a break 2 in the branch at of the telephone-line at the subscribers station, as indicated, and this break, if not closed, will prevent conversation being had over the line. It may, however, be closed in two ways, which I will presently describethat is to say, first, through the front contact of the relay h, and, second, between the terminals e" 't' by the deposit of a coin.

The helix of the relay-magnet 72, whose armature controls through its front contacta bridge across the breakz in the telephone-line, is permanently connected to ground from the side ct of the telephone-line through a retardation-coil and the helices of the polarized coindistributing electromagnet Z.

The tilting armature Z of the polarized ma net Z is connected by means of the arm Z and link m with a swinging stop n, pivoted at n 2 tapes and normally maintained in a position to arrest the passage of a coin through the coinchute 0, wherein the coin-contacts 11?), forming the terminals of the telephone-line a, are located by a centralizing-springp. The swinging valve n is adapted to be moved to one side or the other by the armature Z of the polarized elecrromagnet under the influence of positive or negative direct current which may be sent through the coils-of said magnet, and so to release the coin and allow it to fall, guiding it either into the cash-box chute q orinto the return-chute r, according to the direction in which the armature tilts.

At the central office a pair of connectingplugs tn are provided, between whose tip and ring strands the centralized battery t; is bridged through the usual repeating coil. The battery 1; is grounded at 1). Two keys to w are included in the tip and ring strands of the plug a, which keys are adapted when depressed to open,the tip-strand and connect the ring-strand with a grounded source of.

positive direct current and a grounded source of negative direct current, respectively, through portions of the helix of the relay y, which controls a signal-lamp y.

When the subscriber desires a connection, he first deposits a coin in the coin-chute 0, which closes circuit between the contact-terminalsrlt', the coin resting upon the swinging stop n, which is, as before stated, normally in a central position. He then removes his telephone from its book, thus providing a lowresistance path for the current through his telephone instruments, and current flows from grounded battery 6 by way of the back contact d of the cut-off relay 01 out over the branch a of the line through his instruments and back over the branch at to ground by way of the back contact 01' of the cut-off relay and the line-indicator c. This energizes the magnet of the line-indicator, which thereupon displays its signal and notifies the operator of subscriber As desire for communication. The operator, perceiving the signal, inserts her answering-plug a into the spring-jack Z) of the telephone-line to make connection therewith. The operator is provided with the usual telephone and signaling apparatus associated with her plug and cord circuit in the usual manner and upon ascertaining the Wants of the subscriber endeavors to connect his telephone-line with the one desired. If the connection can be obtained, she disposes of the coin which he has previously deposited by do pressing the cash-box key w. This connects the branch at of the line with a grounded source of positive direct current at a pressure of one hundred and ten volts, which current flows out over the line and to ground at the subscribers station through the coils of the polarized magnet Z. The magnet thereupon attracts its armature in a direction to swing the valve 01 in a contra-clockwise direction, releasing the coin and guiding it into the cashbox chute g. If the connection desired cannot be obtained, however, the other or return key x is depressed, connecting the branch a of the telephone-line with negative direct current at a pressure of one hundred and ten volts, which takes the same path as just described, but causes the polarized magnet to tilt its armature in the opposite direction, swinging the valve n to the left and guiding the coin into the returnchute r. Whichever key is depressed, the operators signal-lamp y is lighted to inform her that the gronndedconnection has been made through the coils of the polarized magnet at the subscribers station and that the coin is properly disposed of. When one of the keys is depressed to dispose of a coin, the current flowing over the branch at of the line energizes v the high-resistance relay h, which thereupon attracts its armature'and maintains the talking-circuit closed through its front contact. The armature of the relay is held in this position after the one-hundred-and-ten-volt current is re moved from the line by twenty-fourvolt current flowing from the grounded centralized battery 1. The polarized magnet is adjusted so as to be unaltected -by twentyfour-volt current.

On ingoing calls the subscriber is permitted to answer and talk without the deposit of a coin in the following manner: The relay h is adjusted to be operated by current at a pressure of twenty-four volts, which flows from the ground 1) through the centralized battery 42, out over side a, of the telephone line, and to ground. The talking-circuit therefore is found to be closed at the front contact of the relay 7?. as soon as the subscriber upon answering the ring at his signalbell lifts his receiver from the hook.

Having thus described my invention, What I claim as new, and desire to secure by Letters Patent, is

1. The combination with a telephone tollline extending from a substation to a central office, of switchcontacts 1' z adapted to be closed by the subscriber, controlling-a break in the telephone-circuit, a relay-magnet connected With'the line at the substation in a branch circuit independent of'said switch' contacts, a switch operated by said relaymagnet for closing said break controlled by the contacts 2' 2', and means controllable from the central office for exciting said relay-magnet, whereby the central-office operator may close the break in the telephone-circuit at the substation independently of the switchcontacts operated by the subscriber, substantially asset forth.

2. The combination with a telephone tollline extending from a substation to a central office, of switch-contacts i 2' adapted to be closed by the subscriber, controlling a break in the telephone-circuit, a battery and a sig naling instrument in the line-circuit at the central office, said signaling instrument be ing responsive to the flow of current in the circuit controlled by said switch-contacts, a relay connected with the line at the substation adapted when actuated to close the same circuit which is controlled by the contacts t' t', and means controlled in making connection with the line at the central office, for actuating said relay, whereby connection with the line at the central office dispenses with the closure by the subscriber of the contacts t' 2', substantially as set forth.

3. The combination with a telephone-line extending from a subscribers station to a central office, of switch-contacts at the subscribers station adapted to be closed by the subscriber, for controlling the circuit through the telephone apparatus, and electromagnetic mechanism, controllable only from the central office, for completing the circuit through the subscribers telephone apparatus independently of said switch-contacts, substantially as set forth.

4. The combination with a telephone-line extending from asubscribers station to a central office, the talking-circuit of said line being normally open at the subscribers station, a relay connected with the telephone-line at the subscribers station and adapted when actuated to close the talking-circuit of said line, a spring-jack terminal for the line at the central office, a plug and its cord-circuit for making connection with said line by way of the spring-jack, and a source of current of suitable character to actuate said relay connected with a contact and said plug,whereby the talking-circuit of the telephone-line is automatically closed by the insertion of the plug in the telephone-line spring-jack, substantially as set forth.

5. The combination with a telephone tollline, of switch-contacts 't' t at the substation of the line, adapted to be closed by the subscriber, controlling the telephone talking apparatus, a relay connected with the line at the substation, adapted to connect the telephone apparatus operatively with the line, and means, independent of the subscriber,

for operating said relay, substantially as set forth.

6. The combination with a telephone-line extending from a subscribers station to a central office, the talking-circuit of said telephone-line being normally open at the subscribers station, a branch circuit at the subscribers station including a relay and a polarized electromagnet, said relay being adapted when actuated to close the talking-circuit of the telephone-line, a signaling-circuit for said telephone-line including a line-indicator at the central office, and a switch at the substation for controlling said signaling-circuit, a plug and plug-circuit at the central office, and a spring-jack for the telephone-line in which said plug is adapted to be inserted to make connection therewith, a source of current suitable for actuating said relay connected with one of the contact portions of the plug, whereby the talking-circuit of the telephone-line is automatically closed by the insertion of the plug in the spring-jack, said polarized magnet being unresponsive to the current for operating said relay, and means at the central office for impressing upon the telephone-line suitable current for the actuation of said polarized magnet, substantially as set forth.

7. The combination with a telephone-line extending from a substation to a central office, said telephone-line being normally open at the subscribers station, of a line-indicator at the central office connected with the telephone-1ine,switch-contacts at the subscribers station for controlling the circuit through said line-indicator, and means, controllable from the central office, for completing the circuit of said telephone-line independently of said switch-contacts, substantially as set forth.

In witness whereof I hereunto subscribemy name this 18th day of May, A. D. 1899.

ALBERT M. BULLARD,

Witnesses:

DE WITT O. TANNER, GEORGE N. BARTON. 

